This continuation of an established program emphasizes the techniques and concepts of cellular and molecular biology, genetics, and fundamental studies of immunology and bone biology of rheumatic diseases. Original population-based clinical research employs rigorous methodological design and statistical analysis. Support is requested for 6 postdoctoral trainees having either an M.D., or Ph.D., or both, as well as for 1 predoctoral (Ph.D candidate) trainee. The faculty are carefully selected in areas of: 1) Basic Biology including, B Cell Biology, T Cell Biology and Antigen Presentation, Bone and Joint Biology and Molecular and Basic Cell Biology, 2) Translational Research in Animal Models in Rheumatic and Immunological Diseases and Human Immunology and Genetics of Rheumatic Disease and 3) Patient-Centered Research in the Epidemiology and Outcomes of Rheumatic Diseases. While the primary strength of the program resides in the direct and individual nature of the interaction in the laboratory between each fellow and the responsible faculty member(s), substantial didactic experiences and the medical school environment supplement training and a series of structures and activities foster interactions. Trainees audit semester courses at Harvard Medical School in their field of basic science, while population science investigators obtain an MPH at the Harvard School of Public Health. Graduate students begin training after completion of course work and are in the Harvard Ph.D Program in Biomedical and Biological Sciences. The program is based in the Division of Rheumatology, Immunology and Allergy at Brigham and Women's Hospital. Importantly, a significant number of faculty are part of the program but located at other Harvard Medical School affiliated Institutions and are selected based on their outstanding scientific and training expertise. They include faculty at 1) the Broad Institute, 2) Boston Children's Hospital, 3) Massachusetts General Hospital, 4) HMS Department of Microbiology and Immunology, and 5) the Harvard School of Dental Medicine. Its goal is to provide an ongoing pipeline of highly trained and expert investigators prepared for and focused in rheumatic disease research.